A light emitting diode (LED) is a semiconductor device converting electrical energy into light energy. The LED is formed of a compound semiconductor producing light of a specific wavelength according to an energy band gap. The usage of LEDs is increasingly being expanded into the areas of optical communications, a mobile display, a display for a computer monitor and the like, a backlight unit (BLU) for a liquid crystal display (LCD), and an illumination device.
Particularly, the development of LEDs for an illumination device requires high current, high flux, and uniform light emission, thereby leading to a demand for developing a new design and process.
Conventionally, in order to emit white light, a light emitting device package has been usually manufactured by applying a compound of a wavelength conversion material such as a phosphor and a transparent resin around an LED chip using a known method such as dispensing. In this case, there is a difference in the amount of wavelength conversion materials positioned on the upper and side surfaces of the LED chip, thereby causing a difference in color characteristics such as color temperature between the white light emitted from the upper surface of the LED chip and the white light emitted from the side surface of the LED chip.
That is, as shown in FIG. 1, the difference in color characteristics such as color temperature leads to the formation of a circular band X called a bull's eye during light emission, thereby causing non-uniform white light emitting characteristics throughout the entirety of the light emitting device package.
Also, when an LED chip mounting area has a cup structure with resin filling the inside of the cup structure, an optical path is extended due to diffusion induced by a wavelength conversion material such as a phosphor, whereby optical efficiency is reduced.